Flap-type rotary abrasive devices having annular arrays of flexible abrasive leaves are commonly used in the abrasive finishing art. Most conventional rotary abrasive devices consist of flexible leaves each comprising a piece of sheet material having abrasive particles bonded on one face thereof. Fabrication of such a rotary device conventionally requires that the abrasive leaves have two notches in their opposite side edges near the base end of each leaf. As the leaves are arranged in an annular array, the notches form concentric circular depressions on opposite sides of the array. Suitable circular reinforcement means such as two metallic end caps mounted on opposite sides of the array are provided, each end cap having an inwardly extending lip which engages the circular depressions thereby mechanically gripping the inner ends of the abrasive leaves. For further anchorage, a suitable adhesive is sometimes introduced into contact with the leaves at their base ends to bond them into a unitary core. Although a rotary abrasive device of the conventional configuration, performs suitably, its manufacture is rather expensive and requires two notches to be formed in each leaf prior to assembly, the forming of these notches being both time consuming and costly because they must be aligned properly with respect to each other and to receive accurate placement of the metal end caps.